For many years now, indicator tubes such as the NIXIE tube of Burroughs Corporation have been widely used in all types of instruments for providing a numerical readout of an electronic circuit logic operation. Such instruments usually include three or more of such tubes, and electronic calculators may include as many as sixteen or more.
According to the present invention, an economic saving can be effected by building the indicator tubes in groups, that is, by providing more than one group of cathode numerals in a single tube envelope, as has been the practice up to now. The present invention provides a novel indicator tube or device including a plurality of groups of cathode electrodes which can be used to display more than one numeral at a time and having novel electrode interconnections and electrode structures.